TCAN1044AEV-Q1: RXD pin pulled to VCC, not VIO

Richard Morrison

Tool/software:

When testing with VCC = 5V, VIO = 3.3V, I have observed the RXD pin erranously being pulled to 5V. I have 10k pullups to 3V3 on each line. Is it possible this is a hardware fault with the IC?

over 1 year ago

0 Michael Ikwuyum over 1 year ago

TI__Guru* 79872 points

Hi Richard,

RXD is referenced to VIO and should not observe otherwise if TXD is also 3.3 V.

It can be IC related if concerns with schematic. You may further confirm if TXD also observes 5 V. If so, supply to VIO may in fact be unstable or TXD's input is 5 V and forcing RXD to 5V. For additional feedback, please help share schematic and waveforms showing VCC, VIO, TXD, RXD, CANH and CANL, thanks.

Best Regards.

Michael.

0 Richard Morrison over 1 year ago in reply to Michael Ikwuyum

Prodigy 10 points

I will take some scope shots tomorrow, but from my observations TXD was not affected, only RXD.

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TCAN1044AEV-Q1: RXD pin pulled to VCC, not VIO